| DE901849C | 1954-01-14 | |||
| DE1144542B | 1963-02-28 | |||
| DE1962009A1 | 1971-06-16 | |||
| US0609509A | 1898-08-23 | |||
| US1081239A | 1913-12-09 | |||
| US1082993A | 1913-12-30 | |||
| US1352256A | 1920-09-07 |
| 1. | Combinut (M) with main nut axially divided into two sections (Mj,M2) and lock nut (M3) c h a r a c t e r i z e d in that the sections of the pair which compose the main nut can, due to the design of the slot (3), easily be identified and oriented in relation to each other, and in that the main nut, on part of its outer perifery, is provided with a thread (2) which, by varying the design of said thread, provides for various degrees of selflocking for the lock nut when said lock nut with its corresponding thread (2) is tightened onto the main nut. |
| 2. | Combinut (M) according to claim 1, c h a r a c t e r i z e d in that the thread (2) between the main nut (M|,M2) and the lock nut (M3) is tapered. |
| 3. | Combinut (M) according to claim 1, c h a r a c t e r i z e d in that the thread (2) between the main nut (M|,M2) and the lock nut (M3) is cylindrical. |
The invention consists of a main nut which is split in two axially and has a section for spanner use and a thread. On to the threaded part, a lock nut is tightened. The slot between the two halves of the main nut is stepped (sawtooth-shaped) in parts to enable easy identification of the two halves forming a pair, and also to prevent misalignement on the thread of the bolt. The nut is designed primarily for use in corrosive environments, and especially for flange assembly of tubing.
The thread between the lock nut and the main nut can have three different designs to suit various requirements. a) ' The thread is cylindrical and may be designed according to metric or UH standards. b) The thread is cylindrical, but cut at an angle which makes the main nut lock onto the bolt if one. pulls on the lock nut after it has been tightened home against the main nut. c) The thread between the nuts is tapered but the design may be varied to give different degrees of locking for the lock nut. The major advantage of the invention becomes apparent when it becomes necessary to remove the nut from severely corroded bolts, and one can unscrew the lock nut from the main nut without being hampered by rust, and then remove the two halves of the main nut without having to unscrew them from the severely corroded bolt.
Designs b) and c) will, in addition to the above- mentioned advantage, also provide a considerable locking effect between the main nut and the bolt. Designs a) and b) provide a reinforced construction as tightening of the lock nut will give
support to the main nut since the section for spanner use is clamped between the lock nut and the object to be bolted.
The Combi-nut consists of parts Mj ,M2 which constitute the two halves of the main nut, and M3 which is the lock nut, illustrated on figures 1,2,3 and 4. The slot 3 between the two halves of the main nut is partly stepped to enable easy identification of two paired halves, and to prevent misalignement on the thread 1 of the bolt S.
The thread 2 between the main nut M3 and the lock nut Mi ,M2 is cylindrical with a wide profile angle α. See Fig. 1. When the lock nut is tightened home against the main nut, the additional torque will clamp the double-threaded section of the main nut against the bolt, and at the same time the section for spanner use on the main nut is supported.
By varying the profile angle α one will be able to obtain various degrees of self-locking effect for the lock nut M3.